(R)-2-(2-aminothiazol-4-yl)-4′-[2-[(2-hydroxy-2-phenylethyl)amino]ethyl]acetic acid anilide has been created by Astellas Pharma Inc., and it has been reported that this compound has not only both an activity of promoting insulin secretion and an activity of enhancing insulin sensitivity, but also an antiobestic activity and an antihyperlipemic activity based on an activity of selectively stimulating a β3 receptor, and is useful in treating diabetes (see, for example, patent literature 1).
Further, it has been reported that the compound can be used as a therapeutic agent for overactive bladder, such as overactive bladder accompanied by prostatic hyperplasia, or overactive bladder accompanied by urinary urgency, urinary incontinence, and urinary frequency (see, for example, patent literature 2).
A clinical trial of (R)-2-(2-aminothiazol-4-yl)-4′-[2-[(2-hydroxy-2-phenylethyl)amino]ethyl]acetic acid anilide in, the form of conventional formulations revealed that pharmacokinetic data unexpectedly varied according to the presence or absence of the intake of food. For example, the rate of decrease of Cmax in a fed state was 67%, and the rate of decrease of AUC in the fed state was 47%, in comparison with those in a fasted state. In this case, Cmax in the fasted state was three times higher than that in the fed state. These problems are considered to be raised by, for example, the changes in pharmacokinetics caused by food, and therefore, the development of a formulation capable of avoiding the effects by food intake is desired.
As a technique of preparing a formulation for modified release, a hydrogel sustained release tablet containing an additive which ensures penetration of water into the tablet, and a hydrogel-forming polymer is disclosed (see, for example, patent literature 3).
However, patent literature 3 does not refer to (R)-2-(2-aminothiazol-4-yl)-4′-[2-[(2-hydroxy-2-phenylethyl)amino]ethyl]acetic acid anilide, and further improvements are needed to produce a pharmaceutical composition.